1. Field of the Invention
The present invention relates to a power converter and a multiport power converter for boosting, bucking down, or regenerating input voltage.
2. Description of the Related Art
As a conventional power converter for boosting, bucking down, or regenerating the input voltage, a DC/DC converter has been disclosed by JP2005-224060A.
The DC/DC converter disclosed by JP2005-224060A is based on switched capacitance and switched so as to allow inductors and capacitors to function selectively, thereby performing any one of the operations of boosting, bucking, and regeneration of voltage.
Further, a power supply device for detecting the output voltage of a plurality of power converters to stabilize the output voltage has been disclosed by JP3182921.
In addition, a DC/DC converter described by JP2006-325694A is such that which has capacitors in common by a plurality of power conversion circuits, thereby miniaturizing a multiport power converter.
However, in the power converter disclosed in JP2005-224060A, on occurrence of overload or overvoltage in performing the operations of boosting, bucking-down and regeneration of voltage, a capacitor is subjected to overload, thus resulting in a possible failure of the capacitor. There is a problem that, despite the above possibility, the power converter is provided only with current protection functions and failure detection based on the current protection functions is unable to detect short circuits of the capacitor, which take place on failure of the capacitor. Further, the power supply device disclosed in JP3182921 can stabilize output voltage. However, it is provided with an individual power converter module for each power converter, thus making it impossible to miniaturize the device as a whole. This is another problem.